Conventionally, image display apparatuses such as projectors have been widely used. For example, light from light sources is modulated by a light modulator such as a liquid-crystal device and the modulated light is projected to a screen or the like, such that an image is displayed. Mercury-vapor lamps, xenon lamps, LEDs (Light Emitting Diodes), LDs (Laser Diodes), and the like are used as the light sources. Among them, solid-state light sources such as the LEDs and LDs have long lifetimes and do not require frequent lamp replacement unlike the conventional case. Further, it is advantageous in that they light up immediately after powered on.
For example, Patent Document 1 has described a light source apparatus using a plurality of laser light sources and an image display apparatus using the same. In the light source apparatus described in Patent Document 1, as shown in FIG. 21, a plurality of laser light sources 31 are provided on a rear side of a phosphor unit 20 capable of emitting white light W including blue laser light B1 and visible light from a phosphor. Then, the blue laser light B1 is emitted from the plurality of laser light sources 31 in the same direction as an optical axis direction of the phosphor unit 20. Such a configuration enables a space 90 on a rear side of two light source sections 32 to be easily ensured as a space for cooling. When a cooling member 95 such as a heat sink and a cooling fan are provided in this space 90, the plurality of laser light sources 31 can be efficiently cooled from a back side 7 (paragraphs [0110] to [0112], etc. of Patent Document 1).
Patent Document 1: PCT International Publication No. WO2014/073152